Insects-2 PDF

VMP 5265 Parasitology Insects – 2 Musca domestica House fly Animals & humans Adults 5.5-7.5 mm Sponging mouthparts Eggs laid in animal manure & decaying organic materials  Musca autumnalis Face fly, animals & human Animal secretions and wounds Eggs laid in rott...

VMP 5265 Parasitology Insects – 2 Musca domestica House fly Animals & humans Adults 5.5-7.5 mm Sponging mouthparts Eggs laid in animal manure & decaying organic materials  Musca autumnalis Face fly, animals & human Animal secretions and wounds Eggs laid in rotting organic materials Eye disorders or conjunctivitis Vector of Draschia megastoma & Habronema Stomoxys calcitrans Stable fly, biting house fly Animals and humans Mouthparts suitable for blood taking Sits on walls head up Eggs on decaying matter such as damp hay Do not treat compost Haematobia irritans Horn fly, around horn after feeding Cattle Half the size of house fly On back in swarm; at abdomen when rained on Eggs in fresh feces Treat host Culicoides spp. Biting midges, “no-see-ums” Animals and humans Short piercing proboscis Painful bite Biological vector of several pathogens  Learning Objectives Become aware of adult flies – Tabanids & Melophagus ovinus Understand myiasis Describe bot flies – Cuterebra spp., Hypoderma spp., Oestrus ovis & Gasterophilus spp. Arthropoda Insecta Diptera Ceratopogonidae Culicoides spp. Tabanidae Tabanus spp. Chrysops spp. Tabanus spp. Common name: Horse fly Hosts: Large domestic or wild animals, humans, small mammals, birds Identification: Stout bodied fly 10 to 25 mm Mouthparts slashing and sponging Zajac and Conboy 2013, Fig. 5.121 Tabanus spp. Tabanus spp. Pathogenesis and lesions: Painful bites Efficient mechanical vectors of several diseases Clinical signs: Annoyance Chrysops spp. Common name: Deer fly Identification: Dark bands across wings Antennae elongate Bite horses in shaded areas Horses will stand in sun to avoid All other aspects like Tabanus spp. Tabanus spp. Chrysops spp. Tabanids Diagnosis: Identify the fly Chrysops spp. prefer shade Treatment and prevention: Cannot control via breeding sites because diffuse and difficult to detect Control in housing and on animals (repellents, insecticides)  Arthropoda Insecta Diptera Hippoboscidae Melophagus ovinus Melophagus ovinus Host: Sheep Identification: Dorsoventrally flattened, hairy, wingless dipterancannot Blood sucking mouthparts fly Site(s) of infestation: Wool UC Davis; http://vetpda.ucdavis.edu/ parasitolog/Parasite.cfm?ID=90 Zajac and Conboy, 2012; Fig. 5.115 Melophagus ovinus Life cycle: Female produces one egg which hatches inside her body Third instar adheres to fleece. Immobile instars pupate (3-4 mm) and visible on fleece Adults emerge in 3 wk in summer, longer in winter Melophagus ovinus Diagnosis: Fly identification Arthropoda Insecta Diptera Culicidae Culicidae (mosquitoes) Culicidae (mosquitoes) Common name: Mosquitoes Identification: Pair of wings, long thin legs, long proboscis, long antennae Genera: 43 Pathogenesis and lesions: Transmit many diseases and pathogens  Myiasis The infestation of living animals with the larvae of dipteran flies Obligatory: can not survive without host (oestrids) Facultative: optional Family Oestridae Adults Large hairy flies Nonfunctional mouthparts Short-lived Larvae Obligatory parasites Host specific Cuterebra, Hypoderma and Oestrus Arthropoda Insecta Diptera Oestridae Cuterebra spp. Hypoderma spp. Oestrus ovis Cuterebra spp. Common name: Rodent or rabbit bot fly, New World skin bot flies Hosts: Rodents, rabbits, squirrels, chipmunks, mice, dogs, cats. Zoonotic Cuterebra spp. Identification: Third instar and season (spring & summer) Adult bot fly (20-30 mm) with vestigial mouthparts. 3rd instar is dark brown and covered with black spines 58 Cycle Cuterebra spp. Site(s) of infestation: Subcutaneous connective tissue, can locate in nasal and oral regions and migrate to brain Pathogenesis and lesions: Fibrotic cyst forms from instar in subcutaneous tissue. Instar in brain of cat can lead to infarction Cuterebra spp. Clinical signs: Lump in neck, fur constantly wet, hole drips fluid Diagnosis: Instar can be removed whole Type 1 hypersensitivity type reaction Wound heals slowly Courtesy of Dr. Steven Graves Courtesy of Dr. Steven Graves Courtesy of Dr. Steven Graves Courtesy of Dr. Steven Graves Cuterebra spp. Treatment and prevention: Several remedies may protect, but are not approved Arthropoda Insecta Diptera Oestridae Cuterebra spp. Hypoderma spp. Oestrus ovis  Hypoderma spp. Common name – adults: warble fly, heel fly, ox warble Common name – instar: cattle grub Host(s): cattle Identification: typical oestrid Hypoderma spp. Sloss et al 1994 Hypoderma lineatum in the frost of Faganstop beback totheesophagus migrates UC Davis 2004 Hypoderma bovis to feet ftp.e Migrate epideral UC Davis 2004  Hypoderma spp. Life cycle: H. lineatum eggs laid in lines of 6 or more on lower limb; adults active at early summer H. bovis eggs laid singly; adults active at late summer  Hypoderma spp. Life cycle: – overwinter as 1st instar H. lineatum accumulates in submucosa of esophagus H. bovis accumulates in epidural fat of the spinal cord Photos: Lyle J Buss, University of Florida  Hypoderma spp. Site(s) of infestation: 3rd instars found in lumps (warbles) on backs of cattle in spring  Hypoderma spp. Pathogenesis and lesions: 3rd instars under skin cause damage and downgrade carcass; economic loss H. lineatum death  bloat H. bovis toxins  paraplegia Noah’s Archive Photo: J.F. Butler, University of Florida Photo: Phillip Kaufman, University of Florida  Hypoderma spp. Clinical signs: faulty regurgitation, bloat paraplegia Diagnosis: identification of parasite Treatment and prevention: Macrocyclic lactones (MCLs) kill early stages Timing – late summer or early fall Arthropoda Insecta Diptera Oestridae Cuterebra spp. Hypoderma spp. Oestrus ovis Oestrus ovis Common name: Sheep nasal bot, warble fly of sheep etc. Hosts: Sheep, goats, llamas, humans Identification: Adults 1 cm long Nasal bots 3 cm long, yellowish- white UC Davis; http://vetpda.ucdavis.edu/ parasitolog/Parasite.cfm?ID=105 Photo: Thomas Nolan Zajac and Conboy, 2012; Fig. 5.113 Oestrus ovis Life cycle: Female deposits 1st instars into nostrils of sheep during flight Overwinter stage (2 wk - 9 mo) Developing bots feed on mucus, cause irritation In frontal sinuses develop to 2nd and 3 instars rd Oestrus ovis Life cycle: Reach 3rd instar stage (3 wk - several mo) before being sneezed out to pupate (4-7 wk) Adults emerge, females survive for 2 wk, depositing 500 instars Early instars on nasal mucosa Facultat de Veterinària de la UAB; http://jcastella.uab.cat/practiques/inici.html Photo: Thomas Nolan Oestrus ovis Pathogenesis and lesions/Clinical signs: Animals expend much energy and lose weight to avoid attacks Instars irritate with hooks and spines Bacterial infection common Oestrus ovis Pathogenesis and lesions/Clinical signs: Aberrant migration through soft pallet may enter brain cavity Humans can become infected in the eye or lip Copious nasal discharge (snotty nose) Aberrant migration of an instar – rare Oestrus ovis Diagnosis: Fly identification Treatment and prevention: MCLs at late summer or early fall and again midwinter  Arthropoda Insecta Diptera Gasterophiliidae Gasterophilus spp. Gasterophilus intestinalis Gasterophilus nasalis Noah’s Archive Noah’s Archive University of Florida extension Theodore Blake RUSVM  host the Inside In the feces  Gasterophilus spp. Life cycle: Egg hatches to 1st instar G. intestinalis: hatches when licked; attached to tongue / lips G. nasalis: hatches spontaneously; crawls into mouth In oral cavity 1st to 2nd instar Swallowed; develop 3rd instar (site specific); live up to 12 mo Pass in feces in spring, pupate 3-9 wk adult fly  Gasterophilus spp. G. intestinalis: Eggs on forelegs and shoulder 3rd instars in non-glandular part of stomach and cardiac region G. nasalis: Eggs on intermandibular spaces 3rd instars attach around pylorus and duodenum G. nasalis/intestinalis 0  Comparison of bot flies G. intestinalis G. nasalis Color in fresh Red Yellow feces Rows of two one spines Site of eggs Forelegs and Intermandibular laid shoulders spaces Site of infestation of Stomach Small intestine 3rd instar Gasterophilus spp. Pathogenesis and lesions: Adult flies an annoyance Attached instars can provoke an inflammatory reaction Clinical signs: Fly worry  Gasterophilus spp. Diagnosis: Differentiate based on color, spines and location in host Seen during gastroscopy Treatment and prevention: Manual removal of eggs Endoparasiticides for instar stages